Furthur earlier in the tour – photo by Vernon Webb

Furthur, which was founded in late 2009 by former Grateful Dead members Bob Weir and Phil Lesh, can’t be accused of being a Grateful Dead cover band. Sure, there are similarities between the two groups. The format is the same, with two sets, plus an encore. Furthur also leavens its shows with songs from the Dead’s repertoire. And as they used to deploy when they were members of the Dead, Lesh drops his patented bombs on bass and Weir dishes his snaky and inimitable riffs on rhythm guitar.

But there are sharp differences, and skeptics who are convinced it’s a nostalgic act are missing the bus, er, boat. For starters, Furthur continues to reignite compositions from the Dead’s psychedelic songbook that the Dead had shelved decades before the band’s demise in 1995, following the death of lead guitarist Jerry Garcia (“Caution/Do not stop on the Tracks” “The Eleven,” “Viola Lee Blues”). What’s more, Furthur is cultivating its own catalog of tunes that is evolving nicely (“Colors of the Rain,” “Seven Hills of Gold”) . So-called Jerry ballads (“Wharf Rat,” “Standing on the Moon”), which in the past were left for quiet contemplation, have morphed into face-melting jams while songs the Dead normally sandwiched between other songs, Furthur now plays individually, giving such tunes a different DNA than in their previous permutations. Furthur drummer Joe Russo plays a more aggressive style than former Dead drummers Mickey Hart or Bill Kreutzmann and lead guitarist John Kadlecik brilliantly channels Garcia’s riffs while simultaneously programming his own crinkly sound on guitar into the process. Backup singers Sunshine Becker and Jeff Pehrson sprinkle the shows with beautiful harmonies. Furthur is also performing an eclectic mix of cover songs that has enthralled fans. The band has been busting out some of the chestnuts from Bob Dylan, the Rolling Stones and The Beatles, among other members of rock royalty. Indeed, at Furthur’s March 20 performance at the Tower Theater in Philadelphia folks were still buzzing about the band’s rendition of most of Side B of The Beatles’ Abbey Road that was performed during Phil’s birthday show March 15 in New York.

The Philly show was the third night of a five-night run at Tower Theater and half way through a month-long tour with few nights off. And at times the band seemed to show some signs of fatigue, making for an uneven performance that, nevertheless, had its share of interesting and inspiring moments.

The first set opened with a blistering “Shakedown Street,” fueled by some gorgeous leads by keyboardist Jeff Chimenti and Kadlecik on guitar, respectively. Kadlecik also shined, using his MIDI (Musical Instrument Digital Interface) to great effect, during a rollicking version of “Good Lovin.’” The band also took “Passenger,” from the Grateful Dead’s Terrapin Station LP, on a wild ride in which the band was clicking on all cylinders. However, this energy wasn’t matched during versions of “West LA Fadeaway,” “Row Jimmy,” and “Casey Jones.”

The second set seemed more enterprising than the first. It had flow and featured more exploration than the first set, but its parts were ultimately greater than its sum. Highlights of the second set included a raging “St. Stephen,” segueing into “Born Cross-Eyed,” and “Sittin’ on top of the World,” featuring nice and dirty leads by Kaledick complemented by Chimenti’s acoustic piano. As a new spring approached, Furthur closed the show with a thunderous “Sugar Magnolia,” which includes the line, “Sweet blossom come on, under the willow, we can have high times if you’ll abide.”

It sounds like a sweet deal. Furthur and its fans seem eager to continue this new conversation. The band is expected to perform regularly for the remainder of this year.